Introduction to Microcontrollers Lab Manual - Microchip

2.2.3 IDE Concepts Watch Window
It is often necessary to be able to determine exactly what is happening to debug a problem
in the program flow. MPLAB IDE provides a Watch window for this purpose.
There are a large number of registers in the File Register window and Special Function
Register (SFR) windows. However, to debug any function, only a small subset of these
are required in order to determine the exact program function. To set up a specific list
of registers to view, you can use the Watch window. To open the Watch window select
View>Watch.
To add an item to the Watch window:
• Choose an SFR or Symbol from the drop-down list and then click the corresponding
Add button
• Drag an item from the SFR, File Register or File window
• Click directly in the window under symbol name and type in the item
The file register address of the symbols is listed first, followed by the symbol name and
finally the value of the symbol.
For this particular lab, the following registers may be of interest:
• WREG15 (Software Stack Pointer)
• WREG0 (Working Register)
• PORTC (LED1 is bit 2)
• T1CON (Timer1 Control Register if you are using Timer1)
• PR1 (Timer1 Preload Register)
• IEC0 (Interrupt Enable Bits)
• IFS0 (Interrupt Flag Status Bits)
FIGURE 2-3: LAB 2 REGISTERS OF INTEREST
2011 Microchip Technology Inc. DS51963A-page 23